Retractable boring assembly



Feb. 28, 1956 F. CARTLlDGE 2,736,542

RETRACTABLE BORING ASSEMBLY Filed Oct. 22, 1954 5 Sheets-Sheet 1 IN V EN TOR.

Fig. 1 BY Frank Cartlidge 7 ZZRL FS Feb. 28, 1956 cARTLlDGE 2,736,542

RETRACTABLE BORING ASSEMBLY Filed Oct. 22, 1954 3 Sheets-Sheet 2 m 3733:3323; a i

gg; 2 BY Frank Cartlidge ATTORNEY Feb. 28, 1956 cA E 2,736,542

RETRACTABLE BORING ASSEMBLY Filed Oct. 22, 1954 5 Sheets-Sheet 3 IN V EN TOR.

BY Frank Cartlidge A T TORNE V Fig. 6

United States Patent RETRACTABLE BORING ASSEMBLY Frank Cartlidge, Chicago, Ill., assignor to Goodman Manufacturing Company, Chicago, 111., a corporation of Hlinois Application October 22, 1954, Serial No. 463,867

2 Claims. (Cl. 262-7) This invention relates to improvements in mobile mining machines of the boring type wherein one or more rotary boring heads, having a plurality of radial cutter carrying arms, are forced into a face of standing mineral such as coal. Such machines are commonly provided with means for reducing the outer diameter of the boring heads to aid in permitting the machine as a whole to be withdrawn from the bore and transported from place to place in the mine. One means previously devised for collapsing the outer ends of the radial arms of the boring head is illustrated in my co-pending application, Serial No. 431,454, and filed May 21, 1954, and consists broadly in hinging the radial arms on the boring head hub so that said arms may be swung forwardly toward and away from the'axis of the boring head. This type of hinged arm structure presents difficult problems in providing suitable means for fully enclosing the arm-hinging mechanism within the hub for retention of lubricant, and also protecting said mechanism from ingress of dirt, grit or the like.

Theprincipal object of the present invention is to pro vide an improved boring head structure of the character described, having a simple seal for the hinge-actuating mechanism effective in all permissible positions of hinged adjustment of the arms relative to the hub.

Other objects of the invention will appear as the following description proceeds.

The invention may best be understood by reference to the accompanying drawings, in which:

Figure l is a front view of a cutter head constructed in accordance with the present invention, showing the hinged arms in fully extended position.

Figure 2 is a side view, in part section, of the cutter head shown in Figure 1, together with the journal bearings for the cutter head forming part of a mobile mining machine.

Figure 3 is an enlarged detail section of the front wiper structure shown in Figure 2.

Figure 4 is a section taken on line 4-4 of Figure 2.

Figure 5 is a section taken along line 5-5 of Figure 1.

Figure 6 is a side view in part section, similar to Figure 2, but with the hinged arms in forwardly collapsed position.

Referring now to details of the embodiment of the invention shown in the drawings, the mobile mining machine has, as usual, a gear housing 21 with a journal bearing 22 embracing a hollow drive shaft 23. The rotatable head includes a hollow hub 24 with a backwardly extending sleeved portion 26 splined as at 27 onto the drive shaft and having an inwardly extending flange 28 connected by cap screws 29 to the end of the drive shaft. Thus, the drive shaft 23 is effective to rotatably drive the hub 24.

The hub 24 includes two hollow radially opening extensions 24a, 24a, each having opposed pairs of transversely spaced ears 31, 31 at their outer ends. A pivot pin 32 extends transversely between each pair of cars 31, 31, as best shown in Fig. 4, and pivotally supports a radially extending arm 33- near the inner end thereof. Each arm 33 is collapsible by hinged movement about pivot pin 32 toward and away from the axis of rotation of the hub. As seenin Figure 2, the outer ends of each radially opening extension 24a between the pair of ears 31, 31 terminate approximately opposite the axis of the pivot pin 32, and the side faces of the arm 3 adjacent the pivot pin extend into close-fitting engagement between said ears. The purpose of this construction will presently be more fully described.

Each of the arms 33 has mounted, as by means of bolts 34-, forwardly projecting brackets 36, 37 on which are mounted cutter bit clusters 38 for cutting kerfs 39 and 41 respectively in a mine face (see Fig. 2). Brackets 36 may as usual be provided with an outwardly-acting wedge surface 42 for breaking up the outstanding core 43 in the manner indicated in Fig. 2.

As best shown in Figs. 1 and 5, the hub 24 is also pro- 7 vided with transverse extensions disposed at right angles to the hollow extensions 24a, and having supporting brackets 46, 46, fixed thereby by bolts 47 and each having a cutter bit cluster 48 effective to cut an inner circular kerf 49 as shown in Fig. 2. Each of the brackets 46 has an outwardly-acting wedge surface 51 effective to break up the core 52.

At the outer end of the hub, and secured thereto by cap screws 53 is a conical burster member 54 with pilot bit means 56 to make the initial entry into the mine face and then break up the inner annular core 57 (Fig. 2).

As shown in Fig. 5, the interior of the hub 24 has a bore 58 within which is reciprocably mounted a slide member 59. An actuating shaft 61 is connected thereto by tapered bearing coupling means generally designated 62 so that the slide member may be moved forward and backward in its bore while the hub is rotating without requiring rotation of the shaft 61, the latter preferably comprising a control rod which is not rotatable. A somewhat similar control mechanism is disclosed in my copending application, Serial No. 431,454.

As best shown in Figs. 2 and 6, the slide member 59 is pivotally connected through a pair of links 63 with the inner end portions of the hinged arms 33.

One of the principal features of the present invention is that each arm 33 is closely fitted for hinged movement within the hollow extension 24a and between the pair of ears 31, 31 thereof, in order to seal the hub against the entrance of dirt and grit and to prevent the loss of lubricant. For this purpose the inner end portion of each arm 33 is provided with front and rear arcuate surfaces A and B struck from the axis of pivot pin 32. Cooperating with surface A is a wiper assembly generally designated 64, while cooperating with surface B is a somewhat smaller wiper assembly generally designated 66. An enlargement of wiper 64 is shown in Fig. 3 where it will be seen that there is a main backup plate 67, a relatively thin retainer plate 68, with a rubberlike wiper sheet interposed therebetween, the whole wiper arrangement being mounted on the outer face of the hollow hub extension 24A approximately opposite the axis of pivot pin 32 and being held in place by cap screws 71. The wiper sheet 69 is pressed firmly into engagement with the surface A.

The wiper assembly 66 of the rear of the hub extension 24a is similarly constructed and arranged, diifering only in the respect that it is relatively short, as shown in the drawings.

Plugs 72 provide closures for openings 72. 1 to afl'ford access to the pivot pins 73 of links 63, for final assembly of the parts, said pins being inserted through those access openings when the slide member 59 is maintained in the position of Fig. 2.

In operation of the machine, it will be understood that the hinged arms 33 are normally extended in a generally perpendicular relation to the axis of rotation of the boring had so as to cut the several circular kerfs at maximum diameter, as shown in Figs. 1 and 2. When it is desired to collapse the hinged arms forwardly to reduce the overall diameter of the boring head, the central shaft 61 is retracted by suitable power means (not shown) at the rear end of the drive shaft, to move the slide member 59 and links 63 to the rear, as shown in Fig. 6. During the resulting hinged movement of the arms, it will be observed that the wiper assemblies 64 and 66 maintain sealed contact at all times with the arcuate surfaces A and B, respectively, on the inner ends of the hinged arms.

Stop means are provided for limiting rearward hinged movement of the hinged arms 33 relative to the hub, in the form shown, said stop means consisting of a pair of forwardly facing blocks 7 mounted on radial extensions 76 of cars 31, and co-acting blocks '77 mounted on lugs 78 extending from opposite sides of the hinged arms (see Figs. 2 and 4). The contact faces of the blocks 77 are generally wedge-shaped as shown to crush any loose material that might be caught between the faces of the blocks.

Although I have shown and described a certain embodiment of my invention, I do not wish to be understood as limiting myself to the exact construction shown and described but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. In a boring head for mining machines, a rotatable hollow hub having a plurality of hollow radial extensions with generally rectangular end openings, each of said extensions having a pivot pin mounted transversely of its end opening, a cutter arm pivotally mounted on each of said pivot pins for limited hinged adjustment toward and away from the axis of rotation of said hub, means enclosed in said hub and connected to the inner ends of said arms for causing simultaneous hinged adjustment of said arms, the side faces of each of said arms adjacent its pivot pin extending in close-fitting engagement into the end opening of its respective hollow radial extension, the portions of each arm forwardly and rearwardly of its pivot pin having arcuate faces concentric with the axis of said pin, and opposed wiper members mounted on the rim of said extension for engagement with the arcuate faces of the arms in all permissible positions of the latter.

2. in a boring head for mining machines, a rotatable hollow hub having a plurality of radially opening extensions, radially extending arms projecting into the open ends of said extensions and mounted in the latter for hinged adjustment toward and away from the axis of said hub, means in said hollow hub for causing simultaneous hinged adjustment of said arms, each hinged mounting for said arms comprising a pair of spaced ears at opposite sides of the end opening of their respective projections, a pivot pin supported at opposite ends in said ears, the front and rear faces of the arm having arcuate faces struck from the axis of the pivot pin, and wiper members fixed to the rim of the end opening between said ears to maintain sealing engagement with the arcuate front and rear faces of said arm in all permissible positions of hinged adjustment of the latter.

No references cited. 

